Clicking Folder Won't Display Image Previews (4th Display Option) Macbook Pro, 2011 model, Snow Leopard, OSX 10.6.8 When I open a folder containing images from the uncluttered desktop, under the right-hand-side or fourth option, which allows scanning horizontally using the scroll wheel, no previews are displayed, only black boxes. The images can be opened individually but I miss the ability to quickly scan and select as above. At the same time my MP3 downloads-to-desktop don't turn black on completion, although the download is performed otherwise normally. What could be causing these quirks? I have not changed any settings. Thanks.